Sarcoma is a type of cancer that originates in the bones or soft tissues of the body, including muscle, tendons, fat, lymph vessels, blood vessels, nerves and tissue around joints. While the tumors can be found anywhere in the body, they form most often in the arms and legs. Additionally, soft tissue sarcoma is not a common type of cancer.
Here is what you should know about soft tissue sarcomas, including risk factors, survival rates, symptoms, and diagnostic tests:
Risk factors for sarcoma
Researchers continue to explore risk factors associated with this rare form of cancer, and potential factors include:
- Exposure to certain chemicals such as Thorotrast (thorium dioxide), vinyl chloride, or arsenic
- Previous radiation therapy
- Certain genetic diseases such as retinoblastoma, neurofibromatosis type 1 (NF1; von Recklinghausen disease), tuberous sclerosis(Bourneville disease), familial adenomatous polyposis (FAP; Gardner syndrome), Li-Fraumeni syndrome, Werner syndrome (adult progeria) and nevoid basal cell carcinoma syndrome (Gorlin syndrome)
- Swelling (lymphedema) in the arms or legs for a long period of time
Survival rates for sarcoma
According to the American Cancer Society, the five-year survival rate is higher for those diagnosed with localized sarcomas (cancer confined to primary site) 81 percent compared to 56 percent for regional stage sarcomas (cancer that has spread to nearby lymph nodes or tissues). However, when sarcomas spread to distant parts of the body, the five-year survival rate is closer to 15 percent.
Symptoms of sarcoma
Soft tissue sarcoma can be difficult to recognize as it can occur anywhere in the body, usually beginning as a painless lump or swelling under the skin. Because sarcoma typically occurs in flexible tissues in the body, it may take time for it to physically appear. Most soft tissue lumps are caused by non-cancerous fat cells, called lipomas, and not sarcoma. It is important to check with a physician if you suspect a lump.
As a sarcoma lump grows and presses on nearby organs, nerves, muscles, or blood vessels, it can cause difficulty breathing, abdominal pain, blood in the stools, or vomit. If a patient experiences symptoms of sarcoma, a biopsy may be done to confirm the diagnosis, with samples potentially taken from the primary tumor, lymph nodes, and other suspicious areas.
Diagnostic tests for sarcoma
Any of the following tests may be performed on the biopsied tissue:
- Immunohistochemistry – the use of special stains to identify the type of cancer
- Light and Electron Microscopy– looking for certain changes in the cell structure or appearance
- Cytogenetic Analysis – looking for certain changes in the chromosomes
- Fluorescence In Situ Hybridization (FISH) – looking at genes or chromosomes in cells and tissues
- Flow Cytometry – measuring the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers on the cell surface